This invention relates to non-invasive methods for differentiating clinical subtypes of Inflammatory Bowel Disease, namely Crohn's disease (CD) and ulcerative colitis (UC). More specifically, this invention relates to a method and apparatus for aiding in the differentiation of Crohn's disease from ulcerative colitis by determining the presence of anti-neutrophil cytoplasmic antibodies (ANCA), wherein the presence of ANCA is indicative of ulcerative colitis. In addition, the presence of fecal ANCA may be used to differentiate ulcerative colitis from other gastrointestinal illnesses such as Irritable Bowel Syndrome.
An estimated 1 million Americans suffer from Inflammatory Bowel Disease (IBD). IBD is characterized by a chronic inflammatory response that results in histologic damage to the intestinal lining. Crohn's disease may involve the entire gastrointestinal tract and include inflammation extending into the transmural mucosa, whereas ulcerative colitis affects solely the large bowel and includes inflammation of the innermost lining. These two distinct diseases require a rapid differential diagnosis for optimal treatment. Conventional methods utilizing multiple endoscopy examinations and histological analysis may take years to confirm a diagnosis. U.S. Pat. No. 6,218,129 discloses a method of determining the presence of serum ANCA as a marker to diagnose IBD. However, it does not disclose a method for diagnosing ulcerative colitis in a patient diagnosed with IBD. Further, the method does not disclose testing human feces for the presence of ANCA.
Accordingly, there remains a need in the diagnostic industry for a non-invasive method of differentially diagnosing ulcerative colitis from Crohn's disease or other gastrointestinal illnesses.